1. Field of the Invention
This invention relates to a tool for starting a nail and for guiding a nail set for setting finishing nails to prevent damage to the workpiece from hammer marks and incorrectly placed nail sets.
2. Description of the Prior Art
Nailing, a common carpentry procedure, is usually accomplished by starting a nail initially holding the nail between the thumb and forefinger of one hand and striking the nail with a hammer held in the other hand. This procedure works well with large, common nails, but it requires more skill with smaller, finishing nails. Some are too short to start; they may not extend beyond the top of the thumb. If misstruck, they can easily bend or being to enter the wood at an angle which can damage the surface of the workpiece.
Devices have been constructed in the past to assist one in starting a nail. Examples of such tools include Sudol, U.S. Pat. No. 3,946,779 (1976) in which a piece of resilent material with a radial slot grips a nail during the initial driving and Biblis, U.S. Pat. No. 2,716,750 (1955) in which nail receiving openings are formed at the intersection of movable jaws. The disadvantages of these tools are that an open slot increases the possibility that a nail can move out of the slot if it is hit incorrectly, and opening and closing jaws complicate a tool.
Once a nail initially engages the workpiece, the nail is driven without anything other than the workpiece holding the nail. If one misses the nail, the resulting damage to the workpiece is very difficult to conceal. If one hits the nail at a slight angle, or off center, it may bend or be at an angle. Even if the nail can be centered again, damage in the form of a larger opening remains. Therefore, it is desirable to have a guard over the workpiece around the nail to prevent the hammer from striking the workpiece and also to assist in holding the nail. The two previously mentioned patents act as guards. See also Auchard, U.S. Pat. No. 2,878,476 (1959).
Once the nail is driven almost entirely into the wood with the top of the nail extending only a very short distance above the surface of the workpiece, it must be driven all the way into the workpiece. Typically, the top of the nail is countersunk approximately 1/8 inch (3 mm) below the surface of the workpiece with a nail set. The initial driving of the nail is stopped with the head slightly above the surface of the workpiece. Unless one stops at that location, the hammer will have struck the wood and left a mark. Once in that position, one drives the nail below the surface of the wood with a nail set. Nail sets, however, occasionally slip off of the small heads of finishing nails creating a hole in the wood next to the nail. It also takes considerable skill to set the nail at the proper depth.
There have been a number of tools developed to assist in setting a nail. Holstein, U.S. Pat. No. 4,008,741 (1977) mounts a nail set in resilient material that is positioned above the nail. The resilent material also surrounds the top of the nail. Striking the nail set with a hammer deforms the resilent material somewhat and allows the bottom of the nail set to drive the nail into the workpiece. Hart, U.S. Pat. No. 2,783,799 (1957) is of a somewhat similar structure, but it holds the nail in a diverging slot. These nail setting tools suffer from similar drawbacks. Because resilient material surrounds the nail, the nail can be offset into the resilient material if the nail strikes a knot or other hard surface in the wood. Hart is not adaptable to different sized nails. With a wider diameter one, for example, the nail will find a different location in the slot such that it will not be centered over the nail set.
It is also difficult in the prior art to determine exactly when the nail is precisely set. Where the materials supporting the nail set deforms, there is a tendency to continue hitting the tool. Where the resilient member is struck, moreover, the material surrounding the nail tends to creep outward during each blow, which tends to leave a mark on the workpiece.